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How do I create a list of random numbers without duplicates?
... = f1.readlines()
for i in range(50):
lines = random.sample(all_lines, 40)
This way, you only need to actually read from the file once, before your loop. It's much more efficient to do this than to seek back to the start of the file and call f1.readlines() again for each loop iteration.
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VIM Ctrl-V Conflict with Windows Paste
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146
From the VIM documentation:
Since CTRLV is used to paste, you can't use it to start a block...
Get the Query Executed in Laravel 3/4
How can I retrieve the raw executed SQL query in Laravel 3/4 using Laravel Query Builder or Eloquent ORM?
20 Answers
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Add a reference column migration in Rails 4
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Rails 4.x
When you already have users and uploads tables and wish to add a new relationship between them.
All you need to do is: just generate a migration using the following command:
rails g migration AddUserToUploads user:refe...
How to convert index of a pandas dataframe into a column?
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Brad Solomon
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answered Dec 9 '13 at 0:39
behzad.nouribehzad.n...
What is Weak Head Normal Form?
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404
I'll try to give an explanation in simple terms. As others have pointed out, head normal form ...
How to validate an email address in PHP
...\\x23-\\x5B\\x5D-\\x7F]|(?:\\x5C[\\x00-\\x7F]))*\\x22)))*@(?:(?:(?!.*[^.]{64,})(?:(?:(?:xn--)?[a-z0-9]+(?:-+[a-z0-9]+)*\\.){1,126}){1,}(?:(?:[a-z][a-z0-9]*)|(?:(?:xn--)[a-z0-9]+))(?:-+[a-z0-9]+)*)|(?:\\[(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){7})|(?:(?!(?:.*[a-f0-9][:\\]]){7,})(?:[a-f0-9]{1...
Is there a foreach in MATLAB? If so, how does it behave if the underlying data changes?
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147
MATLAB's FOR loop is static in nature; you cannot modify the loop variable between iterations, ...
C#位运算符（C#按位与、按位或 等） - 更多技术 - 清泛网 - 专注C/C++及内核技术
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a ^ b
<<
位左移运算
2
a<<4
>>
位右移运算
2
a>>2
1、位逻辑非运算
位逻辑非运算是单目的，只有一个运算对象。位逻辑非运算按位对运算对象的值进行非运算...
What is the memory consumption of an object in Java?
... example, the JVM or native compiler might decide to store a boolean[] in 64-bit long chunks like a BitSet. It does not have to tell you, so long as the program gives the same answers.
It might allocate some temporary Objects on the stack.
It may optimize some variables or method calls to...